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Introduction: Electrophysiological testing has been proposed in the latest European Society of Cardiology (ESC) guidelines for cardiac pacing to identify left bundle branch block (LBBB) patients with infrahisian conduction delay (IHCD) after transcatheter aortic valve replacement (TAVR). While in general IHCD is defined by a His‐ventricular (HV) interval of >55 ms, a cut‐off of ≥70 ms to trigger pacemaker (PM) implantation has been proposed in the latest ESC guidelines. The ventricular pacing (VP) burden during follow‐up in such patients is largely unknown. As such, we aimed to assess the VP burden during follow‐up of patients receiving PM therapy for LBBB after TAVR based on an HV interval > 55 ms and ≥70 ms. Methods: All patients with new‐onset or pre‐existing LBBB after undergoing TAVR at a tertiary referral center underwent EP testing the day after TAVR. In patients with a prolonged HV interval (>55 ms), PM implantation was performed by a trained electrophysiologist in a standardized fashion. All devices were programmed to avoid unnecessary VP by specific algorithms (e.g., AAI‐DDD). Results: 701 patients underwent TAVR at the University Hospital of Basel. One hundred seventy‐seven patients presented with new‐onset or pre‐existing LBBB the day following TAVR and underwent EP testing. An HV interval > 55 ms was found in 58 patients (33%) and an HV interval ≥ 70 ms in 21 patients (12%). 51 patients (mean age 84 ± 6.2 years, 45% women) agreed to receive a PM, out of which 20 (39%) patients had an HV Interval over 70 ms. Atrial fibrillation was present in 53% of the patients. A dual chamber PM was implanted in 39 (77%), and a single chamber PC in 12 (23%) patients, respectively. Median follow‐up was 21 months. The median VP burden overall was 3%. The median VP burden was not significantly different between patients with an HV ≥ 70 ms (6.5 [0.8−52]) and those with an HV between 55 and 69 ms (2 [0−17], p =.23). 31% of patients demonstrated a VP burden < 1%, 27% 1%−5% and 41% > 5%. The median HV intervals in patients with VP burdens < 1%, 1%−5% and >5% were 66 (IQR 62−70) ms, 66 (IQR 63−74) ms and 68 (IQR 60−72) ms, respectively, p =.52. When only assessing patients with an HV interval 55−69 ms, 36% demonstrated a VP burden of <1%, 29% of 1%−5% and 35% of >5%. In patients with an HV Interval ≥ 70 ms, 25% demonstrated a VP burden < 1%, 25% of 1%−5% and 50% of >5% %, p =.64 (Figure). Conclusion: In patients with LBBB after TAVR and IHCD defined by an HV interval > 55 ms, VP burden is relevant in a non‐negligible amount of patients during follow‐up. Further studies are warranted to define the optimal cut‐off value for the HV interval or to develop risk models incorporating HV measurements and other risk factors to trigger PM implantation in patients with LBBB after TAVR. [ABSTRACT FROM AUTHOR]

Introduction: Cardiac resynchronization defibrillator (CRT‐D) as primary prevention is known to reduce mortality. At the time of replacement, higher age and comorbidities may attenuate the benefit of implantable cardioverter‐defibrillator (ICD) therapy. The purpose of this study was to evaluate the progression of comorbidities after implantation and their association with mortality following CRT‐D generator replacement. In addition, a risk score was developed to identify patients at high risk for mortality after replacement. Methods and Results: We identified patients implanted with a primary prevention CRT‐D (n = 648) who subsequently underwent elective generator replacement (n = 218) from two prospective ICD registries. The cohort consisted of 218 patients (median age: 70 years, male gender: 73%, mean left ventricular ejection fraction [LVEF]: 36 ± 11% at replacement). Median follow‐up after the replacement was 4.2 years during which 64 patients (29%) died and 11 patients (5%) received appropriate ICD shocks. An increase in comorbidities was observed in 77 patients (35%). The 5‐year mortality rate was 41% in patients with ≥2 comorbidities at the time of replacement. A risk score incorporating age, gender, LVEF, atrial fibrillation, anemia, chronic kidney disease, and history of appropriate ICD shocks at time of replacement accurately predicted 5‐year mortality (C‐statistic 0.829). Patients with a risk score of greater than 2.5 had excess mortality at 5‐year postreplacement compared with patients with a risk score less than 1.5 (57% vs. 6%; p <.001). Conclusion: A simple risk score accurately predicts 5‐year mortality after replacement in CRT‐D patients, as patients with a risk score of greater than 2.5 are at high risk of dying despite ICD protection. [ABSTRACT FROM AUTHOR]

Background: Due to high failure rates, Medtronic withdrew the Sprint Fidelis lead (SFL) from the market. Passive fixation lead models exhibited better survival than active models, but most studies have limited follow‐up. Aim of this study was to give insights into passive lead survival with a follow‐up of 10 years. Methods: In two large Swiss centers, patients with passive SFLs were identified and data from routine implantable cardioverter defibrillator (ICD) follow‐ups were collected. Patients were censored at time of death, last device interrogation (if lost to follow‐up), time of lead revision (in non‐SFL‐related problems), or at database closure (31th December 2017). We defined lead failure as any of the following: lead fracture with inappropriate discharge; sudden increase in low‐voltage impedance to >1500 or high‐voltage impedance to >100 Ω; >300 nonphysiological short VV‐intervals. Results: We identified 145 patients. Age at implant was 60 ± 12 years with a median follow‐up of 10.2 (interquartile range [IQR]: 5.0‐11.2) years. Thirty‐five percent of patients died after 5.4 ± 2.7 years. A total of 19 leads (13%) failed after 6.7 ± 3.2 years (range: 1.2‐12.0). Overt malfunction with shocks existed in four patients (3%). Cumulative lead survival was 93.1% at 6, 88.2% at 8, 83.8% at 10, and 77.6% at 11 years, respectively, with 35% of implanted leads under monitoring at 10 years. Lead survival fits best a Weibull distribution with accelerating failure rates (k = 1.95, 95% CI 1.32‐2.87, P < 0.001). Conclusions: During very long‐term follow‐up, failure rate of the passive SFL shows an increase resulting in an impaired lead survival of 84% at 10 years. [ABSTRACT FROM AUTHOR]

Background Many patients receiving an implantable cardioverter-defibrillator (ICD) also have atrial fibrillation (AF). Shock testing during ICD implantation carries a potential risk of cardioversion to sinus rhythm (SR) and thrombembolic events. We aimed to analyze the recurrence of AF after cardioversion to SR during ICD shock testing. Methods A total of 555 consecutive patients referred to a tertiary hospital in Switzerland for ICD implantation or generator exchange between 02/2002 and 03/2010 were screened for AF. Fifty-seven patients who were in AF at the time of ICD shock testing were included. Results Forty-four patients (77%) were successfully cardioverted from AF to SR. Type of AF (persistent, not permanent 64 vs 31% of cardioverted patients) was the only predictor. Thirty-nine patients (89%) experienced a recurrence of AF/atrial flutter after a median of 54 days (interquartile range 35-251 days). The only predictor for recurrence of AF was previous AF declared as permanent. No ischemic stroke occurred during hospitalization for the procedure. Conclusions For patients in AF undergoing shock testing at the time of ICD implant, there is a high chance of cardioversion from AF to SR, but there is also a high risk of early recurrence. Decisions regarding long-term anticoagulation should not be based on the heart rhythm immediately following shock testing. [ABSTRACT FROM AUTHOR]

Background The Medtronic Sprint Fidelis lead (SFL; Medtronic Inc., Minneapolis, MN, USA) has a significantly impaired long-term survival, and active fixation leads fare worse than passive leads. The goal of this study was to present data of a series of passive SFL only with very long mean follow-up of more than 6 years. Methods Patients in whom a passive SFL was implanted in two large Swiss centers were followed. We excluded eight (5.5%) patients with a follow-up of <6 months. Patients who died or were lost during follow-up were censored at death or last device check, all others on January 31, 2014. We employed two different definitions of failure: strict = fracture with inappropriate discharge; sudden increase in impedance >1,500 or high-voltage impedance >100 Ohm; >300 nonphysiological short interventricular-intervals. Lenient = any of the above plus a linear increase in impedance >1,500 Ohm or a linear decrease in sensing to a level that treating cardiologists considered inappropriate. Results We included 137 patients. Age was 60 ± 12 years. Mean and median follow-up were 6.2 ± 2.1 and 6.8 (interquartile range 4.8-7.8) years. Applying the strict definition, 12 leads (8.8%) were replaced after 4.9 ± 2.4 years (range 1.2-8.1). Applying the lenient definition, 14 leads (10.2%) failed. Cumulative lead survival was 98.5% at 3, 96.9% at 4, 94.2% at 5, and 93.1% at 6 years. Leads 'at risk' were: n = 122 (89%), 115 (84%), 101 (74%), and 88 (64%). Conclusions In this population with passive SFLs, 5-year lead survival is impaired with 94.2% based on 74% of leads 'at risk' at this time point. [ABSTRACT FROM AUTHOR]

Background To compare the feasibility and efficiency of atrioventricular junction (AVJ) ablation and device implantation in patients with drug-refractory atrial fibrillation using three different approaches. Methods Sixty-nine patients (57% male; age 72 ± 10; ejection fraction 45 ± 15%) undergoing device implantation and AVJ ablation were retrospectively studied at a tertiary referral center. In 20 patients (29%) AVJ ablation was performed via the femoral vein immediately following device implantation (group 1), whereas 33 patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during device implantation through the pocket using the same axillary vein access site (group 3). The main outcome measures were: procedure time, fluoroscopy time, laboratory occupancy time, and success rate. Results There was a significant difference in procedure time (118 ± 45 minutes. in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, P < 0.001) and the laboratory occupancy time (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, P < 0.001). There was no difference in fluoroscopy time (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes P = 0.4). The procedure was successfully completed in all patients, but cross-over to a femoral approach was required in one patient in group 3. Conclusion The alternative approach of AVJ ablation during permanent pacemaker implantation from the same axillary vein access site is feasible and more efficient compared to the femoral approach. [ABSTRACT FROM AUTHOR]

Background To categorize indications of permanent pacemaker (PPM) implantation after transcatheter aortic valve implantation (TAVI), to determine predictors for conduction disturbances and to quantify the need for ventricular pacing during follow-up. Method We studied 97 patients (median age 83 years, 58% female) undergoing TAVI using the Medtronic CoreValve Revalving System (MCRS; Medtronic Inc., Minneapolis, MN, USA) or Edwards-Sapien Valve (Edwards Lifesciences, Irvine, CA, USA). During follow-up, no need for ventricular pacing was defined as <1% ventricular pacing and intrinsic 1:1 atrioventricular (AV) conduction. Results In the 35 patients (36.1%) undergoing PPM implantation three indication categories were identified: (1) high-grade AV block (Mobitz 2 or higher), (2) new-onset left bundle branch block (LBBB) with a prolonged PR interval, and (3) new-onset LBBB. The only independent predictors of high-grade AV block were the use of MCRS (odds ratio [OR] 79.25; 95% confidence interval [CI] 4.57-1373.31) and the presence of preprocedural right bundle branch block (OR 81.95; 95% 95% CI 8.72-770.46). Whereas high-grade AV block resolved only in 17% of cases, none of the patients receiving a PPM due to LBBB with or without PR prolongation required ventricular pacing during follow-up. Conclusion Our findings justify early PPM implantation in patients with high-grade AV block and may suggest a more conservative approach to PPM implantation in patients with new-onset LBBB after TAVI. [ABSTRACT FROM AUTHOR]

Role of Defibrillation Threshold Testing. Introduction: Defibrillation threshold (DFT) testing has been performed to prove functionality of the implantable cardioverter defibrillator (ICD). Over the past years it has become increasingly controversial because of possible morbidity and mortality. The goal of this study was to determine unsuccessful shock testing and report strategies used to overcome these problems. Methods and Results: A total of 314 patients with a de novo implantation of an ICD and 127 patients receiving a generator exchange were identified retrospectively. All patients underwent defibrillation threshold testing after induction of VF using a low-energy T-wave shock during the intervention, 2 shock tests after de novo implantations, 1 after generator change. A safety margin of 10 J or more was requested. Seven (2.3%) patients in the de novo group and 2 patients (1.4%) in the generator exchange group could not be defibrillated using the standard approach. All of those patients had either chronic amiodarone therapy, secondary prevention or a cardiac resynchronization therapy device (CRT). In univariate analysis, amiodarone therapy, dilated cardiomyopathy, and lower ejection fraction were predictors of failure. Conclusion: Our study's results as well as a review of the current literature favor shock testing, especially in patients with specific risk factors as mentioned above. (J Cardiovasc Electrophysiol, Vol. 24, pp. 437-441, April 2013) [ABSTRACT FROM AUTHOR]

Anatomical Predictors for Acute and Mid-Term Success of Cryoballoon Ablation. Introduction: Cryoballoon (CB) pulmonary vein isolation (CB-PVI) for the treatment of paroxysmal atrial fibrillation (AF) has been demonstrated to be safe and reliable. Preprocedural patient selection to address the high variability in pulmonary vein (PV) anatomy may improve the acute and chronic success of CB-PVI. The purpose of this study was to identify anatomical predictors for CB-PVI failure using the 28 mm balloon. Methods and Results : We included 47 patients with paroxysmal AF undergoing CB-PVI with the 28 mm CB. Anatomical global left atrial and PV selective parameters were quantified from 3-dimensional reconstructed preprocedural computed tomography or magnetic resonance imaging data. The mean follow-up was 26 ± 9 months (range: 12-32 months). Multivariate logistic regression analysis revealed that a continuous sharp left lateral ridge between the left PVs and the left lateral appendage (OR, 7.09; 95% CI, 1.17-43.47) and a sharp carina between the left superior and left inferior PV (OR, 5.99; 95% CI, 1.33-27.03) predict acute and mid-term failure. For the right inferior PVs, a non-perpendicular angle between the axis of the PV and the ostial plane (OR, 6.33; 95% CI, 1.20-33.33) and an early branching PV with change in the axis angle (OR, 7.41; 95% CI, 1.44-38.46) were predictors of acute and mid-term failure. Conclusion: Anatomical variables preventing maximal heat transfer from the tissue to the CB could be identified as predictors for CB-PVI failure with the 28 mm balloon. These findings may be a step toward a more tailored ablation strategy based on individual anatomical variations. (J Cardiovasc Electrophysiol, Vol. 24, pp. 132-138, February 2013) [ABSTRACT FROM AUTHOR]